Seal

ABSTRACT

Sealing means for permitting continuous passage of a web material through a gap in a wall separating two zones at different pressures whilst minimising the flow of air from one zone to the other, comprising built into the gap, two bearing members between which the web material passes, the first bearing member comprising a cylindrical roller rotatable about a longitudinal axle and the second bearing member comprising a cylindrical roller rotatable about a longitudinal axle which is parallel to the axle of the first bearing member and which roller comprises a solid cylindrical core the lateral face of which is covered by a layer of a compressible material the distance between the two longitudinal axles being such that the two cylindrical rollers are maintained in contact, sealing means being provided between both bearing members and the adjacent edges of the gap, and its use in apparatus for processing textile material.

United States Patent 1 1 Jamin 1 1 SEAL [75] Inventor: Guillaume Ward .lamin,

Manchester, England [221 Filed: June 3, 1974 [2l] Appl. No.: 475,913

[30] Foreign Application Priority Data July 16, 1973 United Kingdom 33717/73 [52] US. Cl. SOB/3.5 [51] Int. Cl. F16C 33/72 [58] Field of Search 308/35; 226/97. 181', 34/92, 242; 68/5 E [56] References Cited UNITED STATES PATENTS 2,918,069 12/1959 Brown et al, 226/186 X 3.245.334 4/1966 Long 226/97 X 3.281.957 11/1966 Ranney et a1 .4 226/97 X 3.593.901 7/1971 Eltz et a1 226/181 X 3.638.845 2/1972 Herzhoff et a1 226/97 [451 Nov. 18,1975

Primary Examiner-Robert S. Ward. Jr. Assistant Examiner-Gene A. Church Attorney, Agent, or Firm-Cushman, Darby &

Cushman ABSTRACT Sealing means for pennitting continuous passage of a web material through a gap in a wall separating two zones at different pressures whilst minimising the flow of air from one zone to the other. comprising built into the gap, two bearing members between which the web material passes, the first bearing member comprising a cylindrical roller rotatable about a longitudinal axle and the second bearing member comprising a cylindrical roller rotatable about a longitudinal axle which is parallel to the axle of the first bearing member and which roller comprises a solid cylindrical core the lateral face of which is covered by a layer of a compressible material the distance between the two longitudinal axles being such that the two cylindrical rollers are maintained in contact. sealing means being provided between both bearing members and the adja cent edges of the gap, and its use in apparatus for processing textile material.

5 Claims, 4 Drawing Figures US. Patent Nov. 18, 1975 FIG 1 Sheet 1 of 4 U.S. Patent Nov. 18, 1975 Sheet 2 of4 3,920,287

FIG 2 US. Patent Nov. 18, 1975 Sheet 3 of4 3,920,287

FIG 3 US. Patent Nov. 18, 1975 Sheet 4 of4 3,920,287

FIG 4 SEAL This invention relates to an improved seal which enables a textile material to be transferred across a pressure differential whilst minimising the flow of air through the seal.

In the process of vacuum transfer colour printing, a transfer paper which has been printed with one or more disperse dyestuffs is placed with its printed surface in contact with a synthetic textile material in an enclosed chamber which is then evacuated and the paper and material then heated whilst in contact to a temperature which is usually in the region of from 160C to 220C. The chamber is preferably evacuated to a vacuum of at least inches (635 mms.) of mercury, and above all to a vacuum in the region of 27 to 30 inches (685 to 760 mms.) of mercury. When the process is carried out in an intermittent manner a press is used in which the enclosed chamber comprises the space between two platens which is bounded by a sealing strip, the said space being connected to a suitable source of vacuum, and in this type of apparatus there is no difficulty in readily achieving the required amount of vacuum. However in order to carry out the process in a continuous manner it is necessary for the transfer paper and the textile material to be passed over a heated surface inside a vacuum chamber. Whilst the rolls of transfer paper and the textile material, both before and after the heat treatment, can be stored within the vacuum chamber, provision of such storage space markedly increases the size of the chamber thus resulting in increased loads on the chamber due to atmospheric pressure. Further the process has to be interrupted in order to remove the rolls of treated textile material and used transfer paper and to insert new rolls of transfer paper and/or textile material. These difficulties could be overcome by passing the textile material and the transfer paper through a vacuum chamber containing therein the heated surface, the textile material and the transfer paper entering and leaving the chamber through seals which would minimise the entry of air into the evacuated chamber. Whilst the entry ofa small amount of air into the evacuated chamber can be dealt with by means of a suitable source of vacuum, thus enabling the required degree of vacuum to be maintained within the chamber, sealing systems currently available allow too much air to be admitted into the evacuated chamber so that in practice the required degree of vacuum cannot be maintained. The present invention is directed to improved sealing systems which whilst freely allowing the passage of the textile material and/or the transfer paper through the seal minimise the flow of air through the seal.

According to the invention there is provided a sealing means for permitting continuous passage of a web material through a gap in a wall separating two zones at different pressures whilst minimising the flow of air from one zone to the other, comprising, built into the gap, two bearing members between which the web material passes, the first bearing member comprising a cy lindrical roller rotatable about a longitudinal axle and the second bearing member comprising a cylindrical roller rotatable about a longitudinal axle which is parallel to the axle of the first bearing member and which roller comprises a solid cylindrical core the lateral face of which is covered by a layer of a compressible material the distance between the two longitudinal axles being such that the two cylindrical rollers are maintained in contact, sealing means being provided between both bearing members and the adjacent edges of the gap.

The first bearing member can be either a solid cylindrical roller or a roller similar in structure to the second bearing member. The distance between the two longitudinal axles is such that the compressible material on the second bearing member is compressed at a point of contact to such an extent that there is a flat" in the region of 1 cm. wide. the said "flat extending the whole length of the second bearing member. The compressible material which forms the outer layer of the second bearing member and which may be present an an outer layer on the first bearing member is preferably formed of a material such as a flexible polyurethane.

The gap in the wall into which the sealing means is to be fitted is preferably in the form of a rectangle, the long sides of which are preferably horizontal and the length of which is slightly greater than the widest width of the web material which is to be used. The two bearing members are situated adjacent to the long sides of the gap and the lateral face of each of the two bearing members is in close proximity to the two long sides of the gap. Sealing means are provided between the ends of the two bearing members and the adjacent edges of the gap and also sealing means are provided between each of the long sides of the gap and the bearing member which is adjacent thereto. In this latter case the sealing means comprise a flexible sealing strip which bears on the bearing member, or a roller which is in contact throughout its length with both the bearing member and the edge of the gap.

In utilising the seal just described the two bearing members are set in motion so that at the point where they are in contact the lateral faces are moving in the same direction. The leading edge of one or more pieces of material are then fed between the two bearing members and after passing through the apparatus into which the seal has been incorporated are attached to rewind stands. The pressure on one side of the seal is reduced, for example by use ofa vacuum pump, and the materals are then continuously drawn through the seal. However due to the firm pressure which is maintained on the textile materials by the two bearing members and the compressible nature of the outer layer of the second bearing member, little air is drawn through the seal.

Normally the apparatus will contain two such seals, one where the materials enter the apparatus and the other where they leave the apparatus, the pressure within the apparatus being either above or below the pressure, usually atmospheric, outside the apparatus.

By way of illustration, a seal which is a preferred embodiment of the invention will now be described with reference to FIG. I of the accompanying drawings which represents a cross-section of the seal.

BRIEF DESCRIPTION OF THE DRAWlNGS FIG. I is a cross-section of the seal;

FIG. I] is a cross-section of the seal;

FIG. [II is a longitudinal cross-section through an end seal;

FIG. IV is a cross-section of the seal.

In FIG. I, 1 represents the top edge of the gap in the apparatus and 2 the bottom edge of the gap. Two parallel horizontal axles 4 and 5 respectively carry a solid cylindrical roller 3 which is the first bearing member and a solid cylindrical core 6 the lateral face of which is covered by a layer 7 of a compressible material, items 6 and 7 together comprising the second bearing member. The distance between the centres of the axles 4 and 5 is slightly less than the combined radii of the two bearing members, so that, even without the presence of a material 12 between the bearing members the two bearing members are maintained in contact with a flat" 16 being formed on the compressible layer 7 of the second bearing member. A flexible sealing strip 8 which is attached to the top edge I of the gap and runs the full length thereof is maintained in firm contact with the lateral face of the first bearing member 3 by means of a block 9 which is preferably spring loaded. Similarly a flexible sealing strip 10 which is attached to the bottom edge 2 of the gap and runs the full length thereof is maintained in firm contact with the lateral face of the second bearing member, 6 & 7, by means of a block II which is preferably spring loaded. The seal preferably also contains a rigidly mounted guide 13 for the material 12, said guide running substantially the full length of the seal and being fitted with vanes 14 and 15 the ends of which are flexible and are maintained in firm contact with the lateral faces of the first and second bearing members respectively. Sealing means not shown. are provided between the ends of the first and second bearing members and the end walls of the gap. The two bearing members are connected to a source of power, not shown, so that they can be rotated about the axles 4 and 5 in the directions indicated by the arrows.

In operating the apparatus just described the two bearing members are set in motion, a differential pressure is applied across the seal preferably by evacuating the interior of the apparatus, and the leading edge of the material 12 is passed into the guide 13 and then fed between the two bearing members. The material 12 is then continuously drawn through the seal by the rotation of the two bearing members and little air is simultaneously drawn through the seal into the interior of the apparatus.

Preferably two such seals are used in the apparatus, one as an entrance and the other as an exit.

By way of illustration a seal which is a further preferred embodiment of the invention will now be described with reference to FIG. [I of the accompanying drawings which represents a cross-section of the seal.

In FIG. ll, 21 and 22 respectively represent the top and bottom edges of the gap which are separated by a narrow aperture 23 which runs for substantially the whole length of the gap and which serves as an entrance for the material 12. Situated within the apparatus and close to the gap are two horizontal parallel axles 4 and 5 which respectively carry the first bearing member 60 70 and the second bearing member 61 71 both of which comprise a solid cylindrical core 60 or 61 the lateral face of which is covered by a layer of compressible material 70 or 71. The distance between the centres of the axles 4 and 5 is less than the combined radii of the said two bearing members, so that, even without the presence ofa material 12 between the two bearing members. the two bearing members are maintained in contact throughout their full length with a "flat" I6 being formed on the compressible material 70 and 7] of each bearing member where they are in contact. The two axles 4 and 5 are so positioned that the point of contact between the two bearing members is in line with the mid point of the aperture 23. The edge 21 of the gap is extended at the aperture 23 by means of flexible sealing strips 31 and 32 to the lateral surface of the second bearing member 61 71, whilst the lower edge 22 of the gap is similarly extended by means of flexible sealing strips 34 and 35 to the lateral surface of the first bearing member 60 70. The sealing strips 32 and 35 being respectively supported by mounting pieces 33 and 36. Supported on parallel longitudinal axles 24 and 25, which are themselves parallel to the axles 4 and 5, are two solid cylindrical rollers 26 and 27 respectively. The lateral surface of the roller 26 being in contact throughout its full length with the lateral face of the second bearing member 6] 7] and with the flexible sealing strip 31, whilst the lateral surface of the roller 27 is similarly in contact with the first bearing member 60 70 and the flexible sealing strip Each of the said two bearing members and each of the rollers 26 and 27 is connected to a source of power (not shown) so that they rotate in the direction indicated by the arrows. Sealing means, not shown, are also provided between the ends of the two bearing members and the adjacent edge of the gap and also between the ends of the two rollers 26 and 27 and the adjacent edges of the gap.

Apparatus containing the seals as described in FIG. II is operated in the same manner as apparatus containing seals as described in FIG. I.

One method of providing sealing means between the ends of the two bearing members and the adjacent edges of the gap is illustrated in FIG. III of the accom panying drawings which represent a longitudinal crosssection through one such end seal.

In FIG. III the two bearing members 3 and 6 7 are mounted on their respective axles 4 and S which run in bearings 43 and 44 supported in the end wall 40 of the gap. Between the ends of the said bearing members and the end wall 40 is a continuous plate of a thermoplastic material 41 (such as nylon). The end of the bearing member 6 7 is formed from a disc 42 of a hardened ground steel or a thermoplastic material such as nylon which is attached by pins (not shown) to the solid core 6 of this bearing member. The surface of the plate 41 is maintained in contact, even if wear occurs, with the outer surface of the disc 42 and in contact with the end of the first bearing member 3 by means of a number of springs 45 each of which is in a housing 46 in the end wall 40. Situated between the edge of the plate 41 and the end wall 40 is an O-ring seal 47.

By way of illustration, :1 seal which is a still further preferred embodiment of the invention will now be described with reference to FIG. IV of the accompanying drawings which represents a cross-section of the seal.

In FIG. IV, 21 and 22 respectively represent the top and bottom edges of the gap which are separated by a narrow aperture 49 which runs for substantially the whole length of the gap and which serves as an entrance for the material 12. Situated within the apparatus are two horizontal parallel axles 4 and 5 which respectively carry the first bearing member 60 and the second bearing member 61 7! both of which are as previously described. The distance between the centres of the axles 4 and 5 is less than the combined radii of the said two members, so that, even without the presence of the material 12, the two bearing members are maintained in contact throughout their full length with a flat" 16 being formed on the compressible material of each bearing member where they are in contact. The

two axles 4 and 5 are so positioned that the point of contact between the two bearing members is in line with the mid point of the aperture 49. Situated between the said two bearing members and the respective edges of the gap are solid rollers 43 and 41 mounted on horizontal parallel axles 42 and 40 respectively; the solid roller 43 being in contact with the first bearing member 60 70, and the solid roller 41 being in contact with the second bearing member 61 71 so that the compressible outer layer of each of the bearing members is slightly compressed at its point of contact with the appropriate solid roller. Bearing on the solid roller 43 is a shaped plate 47 which runs the full length of the roller, the shaped plate being held in contact with the roller by means of a bellows or spring 48 which likewise runs the full length of the gap. A similar plate 45 is held in contact with the solid roller 41 by a similar bellows or springs 46.

Each of the said two bearing members and each of the solid rollers is connected to a source of power (not shown) so that they rotate in the directions indicated by the arrows. Sealing means, not shown, are also provided between the ends of the two bearing members, the two solid rollers, the shaped plates 45 and 47 and the two sets of bellows and the adjacent edges of the gap.

Apparatus containing seals as described in FIG, [V is operated in the same manner as apparatus containing seals as described in FIG. 1.

Although the use of the seals of the present invention has only been described with reference to a single material 12, this being preferably a textile material of woven or knitted construction or in the form of a soft floorcovering such as carpet, the seal is primarily intended to be used in an apparatus for vacuum transfer printing of textiles, in which case the textile material and a transfer paper in contact with each other can be jointly passed through the same seal. However when using thick textile materials such as carpets it is preferred, in order to avoid wrinkling of the transfer paper, to pass the carpet and the transfer paper through separate seals and then bring them into contact inside the apparatus.

It will be understood that details of the apparatus which has been described may be varied without departing from the essential characteristics of the invention, nor have details been given of the necessary ancilliary equipment such as the power source for the bearing members.

Although the said seal has been particularly described with reference to its use in an apparatus for carrying out the vacuum transfer colour printing of textile materials, the seal can also be used in any other apparatus in which it is desired to transfer a textile material or in fact any material in the form of webs if films across a pressure differential boundary without a substantial flow of air or other gas through the seal.

What we claim is:

l. Sealing apparatus for permitting continuous passage ofa web material through a gap in a wall separating two zones at different pressures while minimizing the flow of air from one zone to the other, comprising a. first and second bearing members between which the web material passes, said bearing members being built into the gap. the first bearing member comprising a cylindrical roller rotatable about a longitudinal axle and the second bearing member comprising a cylindrical roller rotatable about a longitudinal axle which is parallel to the axle ofthe first bearing member and which roller comprises a solid cylindrical core the lateral face of which is covered by a layer of compressible material, the distance between the two longitudinal axles being such that the two cylindrical rollers are maintained in contact,

b. first sealing means provided between the lateral faces of both bearing members and edges of the gap adjacent thereto, and

c. second sealing means provided between the end faces of both bearing members and edges of the gap adjacent thereto, said second sealing means comprising a plate disposed on each side of said bearing members between the end faces of said bearing members and the gap edges adjacent thereto, and a plurality of springs for biasing each plate into contact with the corresponding end faces of said bearing members throughout the length of said end faces.

2. Sealing apparatus as claimed in claim 1 wherein the cylindrical roller forming the first bearing member comprises a solid cylindrical core the lateral face of which is covered by a layer ofa compressible material.

3. Apparatus as recited in claim 1, wherein said second sealing means further comprises an O-ring disposed between the circumferential edges of said plate and said gap edges.

4. Apparatus as recited in claim wherein said plate comprises a first plate and wherein said second sealing means further comprises a second plate disposed between each end face of said second bearing means and said first plate.

5. Apparatus as recited in claim 1 wherein said first sealing means comprises a pair of rollers, each roller being in contact throughout its length with a bearing member and a gap edge adjacent thereto. 

1. Sealing apparatus for permitting continuous passage of a web material through a gap in a wall separating two zones at different pressures while minimizing the flow of air from one zone to the other, comprising a. first and second bearing members between which the web material passes, said bearing members being built into the gap, the first bearing member comprising a cylindrical roller rotatable about a longitudinal axle and the second bearing member comprising a cylindrical roller rotatable about a longitudinal axle which is parallel to the axle of the first bearing member and which roller comprises a solid cylindrical core the lateral face of which is covered by a layer of compressible material, the distance between the two longitudinal axles being such that the two cylindrical rollers are maintained in contact, b. first sealing means provided between the lateral faces of both bearing members and edges of the gap adjacent thereto, and c. second sealing means provided between the end faces of both bearing members and edges of the gap adjacent thereto, said second sealing means comprising a plate disposed on each side of said bearing members between the end faces of said bearing members and the gap edges adjacent thereto, and a plurality of springs for biasing each plate into contact with the corresponding end faces of said bearing members throughout the length of said end faces.
 2. Sealing apparatus as claimed in claim 1 wherein the cylindrical roller forming the first bearing member comprises a solid cylindrical core the lateral face of which is covered by a layer of a compressible material.
 3. Apparatus as recited in claim 1, wherein said second sealing means further comprises an O-ring disposed between the circumferential edges of said plate and said gap edges.
 4. Apparatus as recited in claim 1 wherein said plate comprises a first plate and wherein said second sealing means further comprises a second plate disposed between each end face of said second bearing means and said first plate.
 5. Apparatus as recited in claim 1 wherein said first sealing means comprises a pair of rollers, each roller being in contact throughout its length with a bearing member and a gap edge adjacent thereto. 